Screw rod with washer

ABSTRACT

In a screw rod-washer assembly comprising a screw rod and a plain wahser fitted around the neck of said screw rod, the plain washer is secured to the neck of the screw rod by means of a plurality of projections formed at the inner peripheral edge of said plain washer and projecting close to the outer peripheral surface of said screw rod and, when said assembly further comprises a spring washer, said spring washer and said plain washer are integrally secured to each other by means of an upward annular projection projecting from the inner peripheral edge of the latter and received in the central hole of the former with the upper edge portion thereof bent radially outwardly in a manner to embrace the edge of the central hole of said spring washer, so that the screw rod-washer assemblies of the invention are adapted for mass production.

United States Patent 11 1 Takano Dec. 11, 1973 [54] SCREW ROD WASHERFORElGN PATENTS OR APPLICATIONS i 1 lnvemori Tetslw Takfllw, Toyama,Japan 1,198,187 7/1970 Great Britain 339/263 R Assigneez Takano Seimitsugy Ltd. 381,199 H1931 France 151/38 Nei-gun, Toyama-ken, Japan PrimaryExaminer-Edward C. Allen [22] Flled? 18, 1971 Attorney-James E.Armstrong et al.

[21] Appl. No.: 199,923

[57] ABSTRACT 30 Foreign Application p Data In a screw rod-washerassembly comprising a screw Nov. 19 1970 Japan 45/102323 and a wzlhserfined amund the neck Nov 19 1970 Japan 45/114967 Screw the washer issecurfid to the 9 Mar. 16 1971 Japan 46/17563 the Screw ml by means apluramy of Sept 1971 Japan 46/7535 formed at the inner peripheral edgeof said plam washer and projecting close to the outer peripheral 52 US.Cl. 151/38 85/1 R 85/50 R Surface Screw mi assembly 339/246 thercomprises a spring washer, sa1d spring washer and 51 Int. (:1. ..F16b39/24 wash are 'tegrauy seculed F" [58] Field of Search 85/50 1 R-151/38- means an upward Pmlectmg 339/263 R from the inner peripheraledge of the latter and re- 5 ceived in the central hole of the formerwith the upper [56] References Cited edge portion thereof bent radiallyoutwardly in a mannet to embrace the edge of the central hole of sa1dUNlTED STATES PATENTS spring washer, so that the screw rod-washerassemblies 3,l3l,584 5/1965 Borowsky 151/38 of the invention are adaptedfor mass production 2,254,288 9/1941 Holleran l5l/38 1,547,162 7/1925Bohlman 85/50 R 2 Claims, 6 Drawing Figures SCREW ROD WITH WASHER Thisinvention generally relates to screw rod-washer assemblies used asfasteners and more specifically to screw rod-washer assemblies adaptedfor use, for example, in the tightening of the terminal ends of leadwires to electric equipments or parts.

The connection of the terminal ends of lead wires to electric equipmentsor parts has been effected in some cases by soldering but in most casesby means of screws. This is because the use of screws facilitates theconnection and disconnection of the lead wires and hence is convenientin the assembly and repair of the electric equipments. In connecting theterminal end of a lead wire by means of a screw, a washer is used incombination with the screw, and in addition, a spring washer isfrequently used where there is a fear of the screw becoming loosenedunder vibration or other influences. Therefore, on such occasions itbecomes necessary to use the screw, the plain washer and the springwasher in the form of an assembly. The connection of the terminal end ofa lead wire involves the steps of removing or loosening the screw,lifting the washer, inserting the terminal end of the lead wire'andtightening the screw. Therefore, when the terminal ends, e.g., terminalblocks or terminal lips, ofa large number of lead wires are to beconnected, much time and labor are required for the connecting operationand in addition, two or three parts must always be provided as a set ofassembly. The loss of any one of these component parts renders theassembly useless, whereas a surplus part or parts is or are wasted.Further, it is possible that, during repair work, the washer is lost orthe parts are assembled in a wrong sequence with the result that anabnormally large amount of heat is generated at the connection.

in order to obviate the above disadvantages, it has become necessary to.use screw rod-washer assemblies for the tightening of terminals, and inthe production of such screw rod-washer assemblies there has beenemployed a method which comprises mounting a plain washer or a plainwasher and a spring washer around a screw rod blank before rolling, andcarrying out rolling of the screw rod blank to form a screw rod having afull diameter larger than the diameter of the blank, whereby said washeris assemblied with said screw rod in such a manner that it is notallowed to move off the latter. However, since the rolling is carriedout after the washer is mounted on the screw rod blank, this prior artmethod has been low in productivity and hence not adapted for massproduction. In addition, the production cost of the screw rod-washerassemblies has been high.

The screw rod-washer assemblies according to the present inventionovercome the defects of those produced by the above-described prior artmethod, and are produced by a method in which a screw rod, a plainwasher punched out of a web of blank material and, if necessary, aspring washer punched out of a web of blank material such as a bainitesteel band, are concurrently fed into a die in a predetermined sequence,whereby a screw rod-washer assembly composed of the two or three partsis completed in one step. In the case of producing a screw rod-washerassembly composed of the aforesaid three parts by this method, themethod essentially comprises the steps of forming on the plain washer anannular porjection as means for coupling the spring washer therewith,fitting the spring washer around said projection caulking the projectionradially outwardly, inserting the screw rod into the central hole of theplain washer and then caulking the inner peripheral end of the plainwasher at a plurality of locations to form a plurality of projections toprevent the screw rod from moving off the plain washer.

This method will be described in further detail hereunder: The plainwasher and the spring washer are produced one after another in a commoncontinuous shaping die. Namely, a blank material web of the plain washeris fed into the shaping die in which it is subjected to central holecoining and punching operations and an outer profile shaping operationto form the plain washer. A blank material web of the spring washer isfed into the same shaping die in a direction at right angles to thefeeding direction of the plain washer blank material web-and thereinsubjected to a central hole punching and shaping operation. Thereafter,it is laid above the plain washer blank material web in crossingrelation thereto and subjected to an outer profile punching operation,whereby the spring washer is formed and at the same time the annularprojection of the plain washer is received in the central hole of'saidspring washer and caulked in the way described previously. After theplain washer and the spring washer have been coupled with each other inthe manner described, the screw rod delivered one by one by screw rodfeeder is inserted into the central holes of said washers and then aplurality of projections are formed on the lower surface of the plainwasher, which project toward theneck of the screw rod to hold said screwrod against removal from the central hole of the plain washer. The screwrod-washer assemblies thus produced are removed one by one from thecontinuous webs in the next step.

As described above, the component parts of the screw rod-washerassemblies of the invention, i.e., the screw rod, the plain washer andthe spring washer, each has a shape and a'structure which enable theparts to be continuously easily fabricated and assembled together.Therefore, the supply of completed washers in the production of theassemblies is unnecessary as has been necessary in the production of theconventional ones. Namely, the screw rod-washer assemblies of theinvention are assembled and completed while the washer or washers is orare being fabricated from the blank material web or webs processedthrough one step to another, and therefore, the completed assembly canbe obtained at the same speed as the speed of fabricating the washeronly. In the production of the screw rodwasher assemblies, the step offabricating the washer or washers, the step of assembling the washer orwashers with the screw rod and the step of securing the members to eachother are completed all at once, so that the production rate can beincreased to several times that of the conventional ones and the massproduction is facilitated and further the production cost can besubstantially reduced.

As may be understood from the foregoing, an object of the presentinvention is to provide a screw rodwasher assembly the component partsof each have such a shape and a structure that they can be continuouslyfabricated and assembled and thereby the assembly can be produced at asubstantially higher rate than conventional ones.

Another object of the invention is to provide a screw rod-washerassembly in which the washer will never be allowed to mesh with thethreaded portion of the screw rod during transportation of the assemblyas well as mounting of the washer on the screw rod.

According to the present invention there is provided a screw rod withwasher, consisting of a screw rod and a washer, said screw rod having athreaded portion on one side up to its end on said side and a head atthe other end which is slotted for receiving a screw driver and furtherhaving an unthreaded neck portion between said head and said threadedportion having a diameter substantially equal to the effective diameterof said threaded portion, said washer being a plate-like member having asurface wider than the lower surface of said head and having formed inthe center thereof a punched hole of a diameter larger than the outerdiameter of the threads of said threaded portion, and further saidwasher being rotatably mounted around said neck portion and having aplurality of projections spaced apart from each other and formed at theinner peripheral edge of said washer which projections project radiallyinwardly close to the peripheral surface of said neck portion to preventsaid washer from moving off said neck portion.

FIG. 1 is a front elevational view showing an embodiment of the screwrod with washer according to the present invention;

FIG. 2 is a sectional view looking in the direction of the arrows lI-IIof FIG. 1;

FIG, 3 is a front elevational view partially in section showing anotherembodiment of the screw rod with washer of the invention comprising aspring washer;

FIG. 4 is a vertical sectional view showing in an enlarged scale theessential portion of the screw rod with washer shown in FIG. 3;

FIG. 5 is a verticalsectional view showing a still another embodiment ofthe screw rod with washer of the invention, in which a flange is formedbetween the neck portion and the threaded portion of the screw rod; and

FIG. 6 is a front elevational view showing in an enlarged scale theessential portion of the screw rod with washer shown in FIG. 5.

Embodiments of the present invention will be described hereunder withreference to the accompanying drawings in which similar parts areindicated by same numerals.

Referring to FIGS. 1 and 2, the screw rod with washer, generallyindicated by character S, consists of a screw rod 1 and a plain washer2. At the top end of the screw rod 1 is formed a slotted head 3 which,for example, has a groove 4 formed therein for engagement with a screwdriver, and at the lower portion of the same is formed a threadedportion 5 having screw threads cut from the lower end of the rod at asuitable lead angle. Between the incomplete thread 6 of the threadedportion 5 and the head 3 is formed an unthreaded neck portion 7 of adiameter substantially equal to the effective diameter of the threads 5.The threads at the threaded portion 5 may be of any shape in crosssection, e.g., of a triangular shape or trapezoidal shape, and areformed as by a rolling die. In the embodiment shown in FIG. 1, theincomplete thread 6 of the threaded portion gradually disappears likethat of the ordinary rolled threads. The plain washer 2 may be of asuitable shape such as a circular shape or square shape and is a platehaving an upper surface wider than the lower surface of the head 3 andbeing formed centrally thereof with a punched hole 8 of a diameterslightly larger than the outer diameter of the threads of the screwrod 1. The plain washer 2 is mounted around the neck portion 7 of thescrew rod 1 by having the screw rod inserted from its lower end intosaid plain washer. Further, the plain washer 2 has projections 9 formedon the lower surface thereof at a plurality of locations (four locationsin the embodiment shown in FIG. 2) along the edge of the central hole 8thereof by means of a punch or the like tool, which project radiallyinwardly close the the peripheral surface of the neck portion 7 and bywhich the plain washer 2 is prevented from moving off the screw rod 1.

In another embodiment of the invention shown in FIGS. 3 and 4, a springwasher 10 is mounted around the neck portion 7 of the screw rod 1between the plain washer 2 and the head 3, so as to prevent the screwrod from becoming loosened under vibration or other influences. Anannular projection 11 is formed on the plain washer 2 projectingupwardly along the peripheral edge of the central hole 8 thereof, whilea punched hole 12 of a diameter larger than the central hole 8 of theplain washer is formed centrally in the spring washer 10. The outerperipheral portion of the spring washer 10 is curved to form a raisedportion 13. The annular projection 11 of the plain washer 2 is receivedin the central hole 12 of the spring washer 10 and the upper end thereofis bent radially outwardly by caulking it, whereby the spring washer 10is integrally secured to the plain washer 2.

Still another embodiment of the screw rod with washer of the invention,shown in FIGS. 5 and 6, is of the type consisting of a screw rod, aplain washer and a spring washer, but in this embodiment the screw rod 1is provided between the, neck portion 7 and the threaded portion 5 witha flange 14 extending perpendicularly to the axis thereof and having adiameter substantially equal to the outer diameter of the threadedportion 5. The lead angle of the thread 15 adjoining the flange 14 isabout one-half of that of the other threads, and the helices of thecrest and root of said thread 15 respectively lead to the lower surfaceof the flange 14. Further, the portion 16 of the neck portion 7adjoining the flange 14 is made smaller in diameter than the otherportion of the same to facilitate the formation of the flange 14. Theflange 14 serves to prevent the plain washer 2 from meshing with thethreads 5 during the washer mounting operation and trasportation of thescrew rod with washer.

What is claimed is:

l. A screw rod with washer, consisting of a screw rod and a washer, saidscrew rod having a threaded portion on one side up to its end on saidside and a head at the other end which is slotted for receiving a screwdriver and further having an unthreaded neck portion between said headand said threaded portion, said neck portion having a diametersubstantially equal to the effective diameter of said threaded portion,said washer being a plate-like member without substantial curvature invertical cross-section and having a surface wider than the lower surfaceof said head and having formed in the center thereof a punched hole of adiameter larger than the outer diameter of the threads of said threadedportion, and further said washer being rotatably mounted around saidneck portion and having a plurality of projections spaced apart fromeach other and formed at the inner peripheral edge of said washer whichprojections project radially inwardly close to the peripheral surface ofsaid neck portion to prevent said washer from moving off said neckportion, and wherein a sprng washer having a curved configuration intransverse cross-section is mounted around the neck portions of saidscrew rod between said plain washer and said head and secured to saidplain washer, and a flange portion formed between the neck portion andthe threaded portion of said screw rod and which extends perpendicularlyto the axis of said screw rod and has a diameter substantially equal tothe outer diameter of the threads of said threaded portion, and furtherthe lead angle of the thread of the threaded portion adjoining saidflange is reduced to about one/half of that of the other threads so thatthe helices of the crest and root of said thread may lead to the lowersurface of said flange, respectively, and wherein said plain washer isformed with an annular projection extending upwardly from the innerperipheral edge thereof, while said spring washer is formed centrallytherein with a punched hole of a diameter larger than the diameter ofthe central hole of said plain washer, and said annular projection isreceived in the central hole of said spring washer and the upper endthereof is bent radially outwardly by caulking it, whereby said plainwasher and said spring washer are integrally secured to each other.

2. A screw rod with washer according to claim 1, wherein the part ofsaid neck portion adjoining said flange is reduced in diameter relativeto the other portion of the same, such as to facilitate the formation ofthe flange to enable said flange to prevent the plain washer fromcontacting the threads.

1. A screw rod with washer, consisting of a screw rod and a washer, saidscrew rod having a threaded portion on one side up to its end on saidside and a head at the other end which is slotted for receiving a screwdriver and further having an unthreaded neck portion between said headand said threaded portion, said neck portion having a diametersubstantially equal to the effective diameter of said threaded portion,said washer being a plate-like member without substantial curvature invertical cross-section and having a surface wider than the lower surfaceof said head and having formed in the center thereof a punched hole of adiameter larger than the outer diameter of the threads of said threadedportion, and further said washer being rotatably mounted around saidneck portion and having a plurality of projections spaced apart fromeach other and formed at the inner peripheral edge of said washer whichprojections project radially inwardly close to the peripheral surface ofsaid neck portion to prevent said washer from moving off said neckportion, and wherein a sprng washer having a curved configuration intransverse cross-section is mounted around the neck portions of saidscrew rod between said plain washer and said head and secured to saidplain washer, and a flange portion formed between the neck portion andthe threaded portion of said screw rod and which extends perpendicularlyto the axis of said screw rod and has a diameter substantially equal tothe outer diameter of the threads of said threaded portion, and furtherthe lead angle of the thread of the threaded portion adjoining saidflange is reduced to about one/half oF that of the other threads so thatthe helices of the crest and root of said thread may lead to the lowersurface of said flange, respectively, and wherein said plain washer isformed with an annular projection extending upwardly from the innerperipheral edge thereof, while said spring washer is formed centrallytherein with a punched hole of a diameter larger than the diameter ofthe central hole of said plain washer, and said annular projection isreceived in the central hole of said spring washer and the upper endthereof is bent radially outwardly by caulking it, whereby said plainwasher and said spring washer are integrally secured to each other.
 2. Ascrew rod with washer according to claim 1, wherein the part of saidneck portion adjoining said flange is reduced in diameter relative tothe other portion of the same, such as to facilitate the formation ofthe flange to enable said flange to prevent the plain washer fromcontacting the threads.